Disconcertingly, given the detailed discussions of art and the visual world in The Doors Of Perception, Aldous Huxley was almost blind. Or, at least, some people said he was. Like much else in Huxley's life, the state of his vision was a source of considerable controversy and speculation.

The known facts are these: in 1911, while this scion of one of the UK's foremost intellectual families was studying at Eton, he suffered from a very unpleasant illness called keratatis, which left him blind for several years. Huxley's vision recovered enough for him to study at Oxford, with the aid of thick glasses and a magnifying glass, but further deteriorated over the next 20 or so years.

It's in 1939 that things become murky. Desperate for help, Huxley was persuaded to pursue the Bates Method, a controversial theory (now largely debunked) suggesting, among other things, that glasses shouldn't be worn, natural sunlight could be beneficial and a series of exercises and techniques could help improve vision. He claimed impressive results: "Within a couple of months I was reading without spectacles and, what was better still, without strain and fatigue … At the present time, my vision, though very far from normal, is about twice as good as it used to be when I wore spectacles."

That quote comes from The Art Of Seeing, the book he published about his experiences with The Bates Method in 1942. Reviews, were mixed at best. The British Medical Journal review declared: "For the simple neurotic who has abundance of time to play with, Huxley's antics of palming, shifting, flashing, and the rest are probably as good treatment as any other system of Yogi or Couéism. To these the book may be of value. It is hardly possible that it will impress anyone endowed with common sense and a critical faculty."

In the same article the author suggested that Huxley's vision may actually have improved naturally with time as some conditions move in cycles. Others, meanwhile, doubted that he could see much at all. Wikipedia cites a Saturday Review column from Bennett Cerf published in 1952, just two years before The Doors Of Perception, describes Huxley speaking at a Hollywood banquet, wearing no glasses and seemingly reading from his notes with ease: "Then suddenly he faltered — and the disturbing truth became obvious. He wasn't reading his address at all. He had learned it by heart. To refresh his memory he brought the paper closer and closer to his eyes. When it was only an inch or so away he still couldn't read it, and had to fish for a magnifying glass in his pocket to make the typing visible to him. It was an agonising moment."

In Huxley's defence, he always admitted he still needed a magnifying glass, but whichever way you look at all these arguments, they add an edge to the writer's enthusiastic artistic criticism in The Doors Of Perception. Was he protesting too much? Alternatively, was his delight and concern for the visual world all the more heightened because he had fought so hard to retain his sight – and knew what it means to lose it. Given that The Art Of Seeing had aroused such anger and doubt, was he perhaps using the Doors Of Perception as a way to answer his critics? Is it possible that Huxley's subconscious was operating in ways he didn't care to acknowledge?

Well, maybe. But now I'm in the realm of speculation. Just before I leave, one more conjecture: Huxley wouldn't be entirely delighted at the suggestion the book is somehow about his eye trouble. For him, it was all about mescaline. The message was the drug and its astonishing potential. It marked (forgive me) the high point in a lifelong obsession.

As anyone familiar with Brave New World will know, Huxley's most famous novel also shows the influence of drugs. The citizens of the future are nearly all hopped up on Soma, a powerful hallucinogen that allows "a holiday" from reality, imparts a tremendous feeling of well-being, softens up the mind and poisons the body. In the climactic scene in the book, when John the Savage rebels against Fordist society, his anger is concentrated on Soma, which has come to symbolise all that is rotten in this future-state.

It's fascinating to re-read this earlier book in the light of The Doors Of Perception – especially since, in it, Huxley frequently suggests that Soma is very similar to mescaline in its effects. Back in the 1930s, he even described mescaline as a worse poison than Soma, rendering poor Linda vomitous and even dumber than usual.

Clearly, in the 22 years between the publication of the two books Huxley revised his opinions about the drug. By the time he finally sampled mescaline he was convinced it would offer him insight rather than the distraction from reality offered by Soma. As The Doors Of Perception demonstrates the drug exceeded his expectations. Huxley was to remain a dedicated psychonaut for the rest of his life.

On Christmas Eve 1955, he took his first dose of LSD, an experience he was to repeat often and he claimed allowed him to plumb even greater depths than mescaline. The literary culmination of this self-medication can be seen in Island, the 1962 novel, which can be viewed as an answer to Brave New World. It describes a utopia rather than a dystopia, and this time around drugs perform an entirely beneficial function, providing serenity and understanding. They are as the book puts it, "medicine".

Ironically, Pala, Huxley's utopia sounds even worse than the alternative future Huxley describes in Brave New World. The Palanese are crashing bores. They are the kind of people who (in one of the most inadvertently hilarious passages I've read) think it's OK to rewrite the climax of Oedipus Rex with a lecture from some Palanese children, who inform the luckless mother-lover that he is being "silly" and ought to follow their philosophy rather than tear his eyes out … But never mind that. Although it is awful in many regards, Island still holds the charm of Huxley's cultured prose and fertile mind. The knowledge that he wrote the book shortly after his first wife died from cancer and he himself had received a terminal diagnosis also adds real poignancy to the book's many passages about coping with disease. One of his ideas is that tripping may ease the passage into that good night – advice he famously took on 22 November 1963 when he asked his wife second wife Laura Huxley to give him LSD. "Light and free you let go, darling; forward and up," she whispered to him as he drifted away. "You are going forward and up; you are going toward the light."

We'll never know how Huxley's final trip went, but we do know that his psychedelic experiments had a remarkable afterlife. (Psychedelic, incidentally, was a word Huxley helped coin along with Humphry Osmond. Huxley can lay considerable claim to kick-starting the 1960s revolution in the head. It wasn't just the fact that The Doors Of Perception was so influential. He was also personally instrumental in introducing luminaries like Allen Ginsberg and Timothy Leary to the possibilities of psychedelic experimentation (as described in the early pages of Martin Lee and Bruce Shlain's Acid Dreams, the definitive story of the way LSD swept through America in the 1960s – thanks to the many contributors Reading group who recommended that).

It's safe to say that Huxley changed the world. Without him there might have been no turn on, tune in, drop out, no Merry Pranksters, no Sergeant Pepper, no Fear and Loathing in Las Vegas, no Focus.

I scoffed when I read JG Ballard's introduction to my edition of The Doors Of Perception and he said that the book was "even more prophetic" than Brave New World (and also, incidentally, that Brave New World is more prophetic than Orwell's 1984). As this Reading group month draws to a close, I can see that – as usual – Ballard was quite right. The book didn't just point the way to the future (or one potential version of it), it changed it. The big question now is whether it has opened any doors for you? Has Huxley changed your view of mescaline and/or reality? And are you tempted to follow in his footsteps?